Clamps the character ranges for which bounds are requested so that they fall within the number of p…

content/browser/accessibility/browser_accessibility.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/accessibility/browser_accessibility.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 438 matching lines @@
     int local_end = overlap_end - child_start;
     // |local_end| and |local_start| may equal |child_length| when the caret is
     // at the end of a text field.
     DCHECK_GE(local_start, 0);
     DCHECK_LE(local_start, child_length);
     DCHECK_GE(local_end, 0);
     DCHECK_LE(local_end, child_length);
 
     const std::vector<int32_t>& character_offsets =
         child->GetIntListAttribute(ui::AX_ATTR_CHARACTER_OFFSETS);
-    if (static_cast<int>(character_offsets.size()) != child_length)
-      continue;
+    int character_offsets_length = static_cast<int>(character_offsets.size());
+    if (character_offsets_length < child_length) {
+      // Blink might not return pixel offsets for all characters.
+      // Clamp the character range to be within the number of provided pixels.
+      local_start = std::min(local_start, character_offsets_length);
+      local_end = std::min(local_end, character_offsets_length);
+    }
     int start_pixel_offset =
         local_start > 0 ? character_offsets[local_start - 1] : 0;
     int end_pixel_offset =
         local_end > 0 ? character_offsets[local_end - 1] : 0;
 
     gfx::Rect child_rect = child->GetPageBoundsRect();
     auto text_direction = static_cast<ui::AXTextDirection>(
         child->GetIntAttribute(ui::AX_ATTR_TEXT_DIRECTION));
     gfx::Rect child_overlap_rect;
     switch (text_direction) {
@@ skipping 19 matching lines @@
                                        child_rect.width(), bottom - top);
         break;
       }
       case ui::AX_TEXT_DIRECTION_BTT: {
         int bottom = child_rect.bottom() - start_pixel_offset;
         int top = child_rect.bottom() - end_pixel_offset;
         child_overlap_rect = gfx::Rect(child_rect.x(), top,
                                        child_rect.width(), bottom - top);
         break;
       }
-      default:
-        NOTREACHED();
     }
 
     if (bounds.width() == 0 && bounds.height() == 0)
       bounds = child_overlap_rect;
     else
       bounds.Union(child_overlap_rect);
   }
 
   return bounds;
 }
@@ skipping 712 matching lines @@
       }
     }
 
     node = container;
   }
 
   return gfx::ToEnclosingRect(bounds);
 }
 
 }  // namespace content